Water gauge for steam boilers



July 3, 1928.

O. H. HARTMANN ET AL WATER GAUGE FOR STEAM BOILERS Filed March 9, 192'?2 sheets sheet 26K 16 .11 l l I la 1 v 022011. Jfarjm Jwuemtozs July 3,1928.

O. H. HARTMANN ET AL WATER GAUGE FOR STEAM BOILERS Filed March 9, 19272v s eets-sheet 2 gwomtm 21 Harjimarm,

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Patented July 3, 1928.'

OTTO H. HARTMANN AND HEINRICH MANY, ASSIGNORS TO SCHMIDTSCHE PEPER-KORN,OF KASSEL-WILHELMSHOHE, GER- HEISSDAMPF-GESELLSCHAFT, M. B. H., O!

KASSEL-WILHELMSHOHE, GERMANY, A CORPORATION OF GERMANY.

WATER GAUGE FOR STEAM BOILERS.

Application filed March 9, 1927, Serial No.

- This invention relates to Water gauges for high pressure steamboilers. In gauges designed to withstand pressure of 30 to 100atmospheres, rupture of the glass frequently occurs, and we have foundexperimentally that the cause of such rupture lies not so much in thestresses due to temperature and pressure as in the stresses arising fromthe unequal distribution of the pressure of the retaining means on theglass.

In order to secure a more equal distribution of pressure, it has beenproposed to use .a glass disk secured in place by a threaded cap havingan observation opening, but this construction makes it difficult toobtain a steam-tight packing. Slotted securing plates held in place bynumerous bolts or screws are commonly used, but this constructionresults in an unequal distribution of stresses, and makes it difficultto replace the glass in case of rupture.

The present invention aims to eliminate these objections by providing agauge wherein the retaining means bear evenly on the glass, the stressesbeing automatically equalized, and wherein the task of replacement isconsiderably simplified.

The invention is illustrated in the accompanying drawings, in which,

Fig. 1 is a side elevation of one unit of a gauge embodying theinvention,

Fig. 2 is an enlarged section on the line 2-2 of Fig. 1,

Fig. 3 is a similar section showing a modified form,

Figs. 4, 5, and 6 show various ways of arranging the units in use.

Referring to Figs 1 and 2, the unit consists of a body 10 having avertical bore 11 which communicates with the interior of the boiler bymeans of pipes 12 and 13. Valves 14 and 15 of any suitable constructionare provided to cut the unit out of communication with the boiler whendesired. The unit comprises upper and lower sections 8 and 9. of whichone section will now be described.

A vertical slot 16 extends from bore 11 to the front face of the body10, and a glass 17 is fitted over the slot. The glass is held in placeby a cover plate 18, provided with a slot 19 thru which the height ofwater may be observed. Suitable packing 20 is provided at both surfacesof the glass.

173,855, and in Germany February 20, 1926.

At the rear of the gauge and spaced from the body ,10 is a pivot pin 21mounted in horizontal flanges 42 extending rearwardly from body 10, andequalizing levers 22 are mounted on the pivot pin. Links 23 arepivotally connected to levers 22 and to plate 18 at one side of thegauge, while at the other side are threaded links 24, pivotallyconnected to levers 22 and at their other ends adjustably secured inslots 30 of plate 18 by means of nuts 25. It will be seen that plate 18,lever 22, and links 23 and 24 form a retaining frame, members of whichare pivotally connected together.

In order to prevent displacement of the glass 17 and packing 20, collars26 and 27 are provided, being removably secured to plate 18 and body 10by any suitable means, and extending entirely around the glass 17.

The portions of body 10 and plate 18 which form bearing surfaces for theglass, are raised slightly above the adjacent material. the object beingto facilitate grinding of the surfaces to make them accurately plane.These bearing surfaces will of course be accurately ground before thegauge is assembled, so that the pressure on the glass will be evenlydistributed, and the purpose of having the bearing surfaces raised is topermit such grinding to be done either by machine or by hand withoutinterference from adjacent parts. If it is found necessary to grind thebearing surfaces after the gauge is assembled, this is possible byremoving collars 26 and 27. If desired, the bearing surfaces may be madesmaller than the glass, as by beveling the material as indicated at 28.It may also be found advantageous to bevel the edges of the glass inorder to relieve them of all stresses.

In the construction justdescribed, it will be readily seen that when thenuts 25 are tightened, they will produce compression on the glass. butthat the compressive stresses will be distributed by the action of lever22, which acts as an equalizer. It should also be noted that in order toreplace a broken glass it is necessary to loosen only two nuts,whereupon the links 24 may be swung laterally out of slots 30 toentirely release the retaining frame.

In the'modification shown in Fig. 3, the

retaining frame comprises hooks 31 which the component in the coverplate 18 to hold it in place. The hooks are pivoted to an equalizing bar32, and tension is applied to them by means of a bolt 33 threaded in bar32 and having a rounded end 34 seated in a recess at the rear of body10. This arrangement permits the bolt to rock on its rounded end as apivot, so as to allow the retaining frame to equalize the compression onthe glass. A threaded bushing 35 is provided to prevent the boltdropping out when the retaining frame is loosened, but is shaped topermit the bolt to rock as described above. A pin 36 engages in a slotin one of the hooks to adjustably secure it to cover plate 18.

As will be evident from Figs. 4, 5 and 6, the bolts 24 should referablybe arranged at the outer edges of the gauge, so that the nuts on themwill be readlly accessible.

It will be noted that the upper and lower sections 8 and 9 have upperand lower slots 19 spaced vertically from each other. In order to permitreading of water levels falling between the two slots, an arrangementsuch as is shown in Fig. 4 may be used, wherein two units are placedside by side in staggered relation, or the gauge may comprise threesections arranged as shown in Fig. 5. A further possible arrangement isshown in Fig. 6, where two sections are disposed in inclined overlappingrelation to perrpit reading the gauge at. any possible leve Havingdescribed our invention, what we claim as new and desire to secure byLetters Patent of the United States is:

1. A water gauge for high pressure boilers, comprising a hollow memberadapted to be connected to a boiler and havin a longitudinally extendingaperture, a g ass fitted over said aperture, and a frame for retainingsaid glass in position, said frame consisting of members pivotallyconnected together end to end in series, with one of the intermediateframe members bearing on said hollow member.

2. A water gauge for high pressure boilers comprising a hollow memberadapted to be connected to a boiler and havin a longitudinally extendingaperture, a g ass fitted over said aperture, and a frame forretainengage in notches ing said glass in position, said framecomprising an equalizing member pivoted on the hollow member a coverplate engaging the side of the glass opposite the aperture, and linksconnecting the equalizing member with the cover plate.

3. A water gauge as recited in claim 1, wherein the hollow member andthe frame are provided with plane bearing surfaces for said glass, thesaid surfaces being raised to facilitate accurate machining, andcomprising in addition a pair of collars adapted to prevent lateraldisplacement of the glass, said collars being removable to permitaccurate machining of said surfaces.

4. A water gauge for high-pressure boilers. comprising a hollow memberadapted to be connected to a boiler and having a longitudinallyextending aperture, a glass fitting over the said aperture, a frame forretaining said glass in position, said frame being connected pivotallywith the hollow member, the hollow member and the frame being providedwith plane bearing surfaces for said glass, the said surfaces beingraised to facilitate accurate machining, and collars adapted to preventlateral displacement of the glass, said collars being removable topermit accurate machining of said surfaces.

5. A water gauge as recited in claim 1,

in which the frame comprises an equalizing member pivoted to the hollowmember, a cover plate, a link connecting the equalizing member with thecover plate, a second link pivotally secured to the equalizing memberand detachably secured to the cover plate, and threaded meansco-operating with said second link to press the said cover plate towardthe said hollow member.

6. A gauge comprising a tubular member adapted to be connected to acontainer and having a longitudinal aperture, a transparent memberfitted over said aperture, a cover plate having a sight opening andhaving a raised surface contacting with the outer surface of saidtransparent member, and means for holding said raised surface againstsaid transparent member.

In testimony whereof we aifix our signatures.

OTTO H. HARTMANN. HEINRICH PEPERKORN.

